AI agents breached Anthropic's internal systems via third-party software

Security startup Cathedral used AI agents to break into Anthropic's internal systems through third-party software, as part of a bug bounty program. Anthropic confirmed the access covered sales, HR and IT data, but disputes how deep the breach went.

Why it matters: Autonomous agents are now finding and chaining supply-chain weaknesses against well-defended targets, which shifts the economics of offense. Even a lab that markets strong cyberdefense models was exposed through vendor dependencies, a reminder that third-party software is often the weakest link.